While most people recognize clean water and air as key aspects of environmental balance and maintaining natural habitats, a large proportion of them fail to notice the importance of what lies beneath their feet. According to Henry Lin, a hydrologist from Pennsylvania State University (Penn State), the ground is just as important a factor when it comes to a clean environment.

Lin, who is a professor in hydropedology and soil hydrology at the university, explained that more understanding of the components that make up soil is essential for protecting it from pollution and other destructive processes. The ground acts as a natural filtration and purification system, so keeping it clean can contribute to better underground water quality and improved environmental management.

Speaking at the annual meeting of the American Association for the Advancement of Science in Boston, Lin said that the outer layer of the earth, from the vegetation covering the ground to the various layers of underground materials, can soak up and clean water by extracting excess nutrients, heavy metals and other impurities. The ground can also serve as a storage container for freshwater, making it key to sustainability. There is no life without water but many people seem to be unaware that there is no clean water without groundwater, he said.

About two-thirds of the global annual precipitation lands on the ground, meaning that there is more fresh water underground that there is in lakes and rivers, Lin went on. Fresh water is not only used for drinking. In fact, a significant part of the fresh water available is used for irrigation purposes and in various industrial processes, he pointed out.

Lin's view is supported by the findings of a joint study by Canadian and Dutch scientists released last year. Their research found that underground water was used at rates which do not allow water reserves to replenish, leaving 1.7 billion people stuck in areas where underground water reserves were running dangerously low. The problem was most pressing in Asia, the scientists found.

The problem needs to be dealt with urgently, Lin stated. People should be educated about the importance of the ground for the environment in a similar manner to the way they are informed about food security, waste and recycling. He believes that a "blue revolution" can improve policies and lead to a state of water security, which would guarantee clean, safe and reliable water supply in every corner of the world.

According to Lin's research, management policies that are currently in place in a large part of the world fail to run resources properly and do not provide effective practices to ensure that groundwater is protected from various human-related factors, including land use, construction agriculture and underground storage. He called for a bigger focus on sustainability on the part of planners, municipalities and agriculture businesses.